Injera is a sourdough risen flat bread that is primarily an Ethiopian staple food, but increasingly becoming popular in Ethiopia's neighboring countries and around the world. Injera is made of a grain called Teff but increasingly other grains by themselves or mixed with Teff are being used in making Injera. Injera is soft, thin and flexible with porous features (eyes) on one side and smooth on the other. It is large in diameter usually ranging from 12 to 24 inches. Injera requires a fermented batter with a right chemistry to fulfill the above features.
Traditionally the process of making Injera requires 3 steps.
Step 1: Spreading a thin batter on a hot non-sticking griddle or earthenware in a thin and uniform manner over a large diameter surface.
Step 2: Put a cover on top of the griddle, effectively creating a dome, that traps the steam from the cooking batter hence making it soft. While cooking, the fermented batter on a hot griddle creates a porous surface on top and a smooth surface at the bottom.
Step 3: After a certain amount of time, the cover is removed and the Injera will be taken off-of the griddle to be cooled down.
The soft, thin and large size nature of Injera makes it hard to flip or push as it is done in making pancakes, tortillas or other breads. Therefore an automated machine that can be utilized to make Injera has been very challenging.
Of the three steps mentioned above, this invention emphasizes on the first important step. The second step can be achieved easily by employing any pick and place robot arm that does not need any invention. But the third step, removing and cooling, still to be done manually, may need another invention in the future.
Therefore this semi-automated invention will greatly solve the most challenging part of the Injera making process—The first step mentioned above. When this step is laid out in multiple stations, it lends itself to be used in mass production of Injera to the satisfaction of customers. This system also can be used for other flat thin breads that have low viscosity batter.
Prior patents e.g. U.S. Pat. No. 7,421,943 B1 and U.S. Pat. No. 7,063,008 B2, to the best of the inventor's knowledge, did not address sufficiently the problem of spreading the batter on the hot surface/griddle, which is one of the main inventions of this art described here.
In case of Injera Manufacturing System (U.S. Pat. No. 7,063,008 B2) the spreading utilizes air or air pressure to accomplish the spreading. The use of air to spread the batter will have undesirable effect on the forming of the porous top surface (eyes), which has a negative impact on the characteristics of the Injera.
Moreover, in case of Injera Manufacturing System, the batter is being spread and cooked to make Injera while it is on a conveyor system. In this invention the batter spreading and cooking of the Injera is performed on a stationary griddle/hot surface while the batter-spreading embodiment is moving.
In case of Injera Baking Machine (U.S. Pat. No. 7,421,943 B1) the spreading is done in a spiral way. Compared to a single circular motion of this invention, the spiral way takes time that will have a cook time uniformity issue, which will have an impact on the quality of the Injera. Also the Injera Baking Machine is a single-station baking machine that doesn't lend itself well to mass production. Moreover it does not mention one of the most important steps, having a cover during cooking.